I think you've all seen the sequential flashing of an airport's runway lights when approaching an airport. The flash sequence appears to be wired so that the lights always "run" towards the end of the runway.

Now imagine that you approach an airport in a small plane and see that the runway lights are running away from you. You land, then take off immediately and look back to the runway. The lights still run away from you, now towards the other end. While on approach the lights moved in the same direction as your airplane, they now seem to go into the opposite direction.

What might be the explanation for that phenomenon? Does the tower always change the direction of the light sequence depending on whether an airplane is taking off or landing? Or could there be another explanation?